geography revision

NATURAL HAZARDS

natural hazard - extreme natural events that have the potential for the loss of human life ( these include earthquakes, volcanic eruptions, tsunamis ect )

factors such as how densly populated an area is, the magnitude of the event or the rock type presemt during events like earthquakes, all impact the risk ot the hazard and its danger levels.

TECTONIC HAZARDS

tectonic hazard - a hazardous event that occurs when the earth's crust moves. for example when plates move they may bcome stuck due to friction, this builds tension which ends in the plates slipping, releasing an earthquake

plate tectonic theory - 

there are 3 types of plate margins: destructive, constructive, conservative

destructive plate margins: when oceanic and continental plates move together. the denser oceanic plate is forced under the lighter continental plate where it is melted due to friction. this produces magma which allows for the formation of  volcanos

constructive plate margins: when terctonic plates move away from eachother. this pulls the earths crust apart to allow magma to rise. volcanos can sometimes occur here, although they mostly occur at destructive plate boundaries along with most other natural hazards.

conservative plate margins: when plates slide past eachother. they cause friction and as a result of this are the site for many shallow focus earthquakes

EARTHQUAKES

earthquakes - the release of pressure when 2 plates suddenly slip past each other

primary effects - people killed, homes destroyed, roads/railways destroyed ect

secondary effects - slowed economy, burst water pipes ( disease and thirst )

immediate responses - warnings, rescue teams, aid provided

long term responses - rebuilding homes and transport lines, installing monitoring equipment

CASE STUDIES: 

LIC -  haiti ( 2010 )#

primary effects - 220,000 deaths, 300,000 injured, main port badly damaged

secondary effects - 2 million left with no food/water, increase in crime

immediate response - 20 million dollars donated by government, USA sent rescue teams

long term responses - homes rebuilt to a higher standard, port rebuilt 

HIC - christchurch ( 2011 )

primary effects - 181 killed, 2000 injured, over 50% of cities buildings danaged

secondary effects - buisnesses close for a very long time, schools closed for 2 weeks

immediate responses - $6-7 million international aid, red cross sent aid workers to help

long term resonses - water and sewage restored, temporary housing provided

RISK MANAGEMENT

what is risk management - risk management is the process of identifying, monitoring, and managing potential risks in order to minimise the impact that they have .

why do people still live in areasd at risk? - this is usually because the person believes that the advantages outweigh the disadvantages.

advantages - good fertile soils, geothermal energy (economic) , cant afford to leave , have family nerby

MONITORING - monitoring is when scientists watch the signs given out by , for example, an active volcano. they will check these signs to make sure there is no likely erruption and if so, they will issue out a…